Alloy steel



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ALLOY STEEL.

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To all whom it may concern:

Be it known that we, GEORGE WV. SARGENT, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, and J osEPH WV. W'EITZENKORN, a resident of Washington, in the county of lVashington and State of Pennsylvania, have invented a new and useful Improvement in Alloy Steel, of which the following is a specification.

The invention relates to alloy steels and has particularly to do with so-called silicomanganese steels used extensively for springs, gears, and similar articles, although the invention is not limited to steels for any specific purpose, or to articles made of any particularsteel.

In silic'o-manga-nese steels, silicon is gen erally considered to make the steels tough so that they are less liable to break particularly when subject to shock, and manganese is considered to give the steels increased tensile strength. It is well known that these steels are very sensitive to heat treatment, and that unless carefully manufactured and heat treated the become brittle and hence unsuitable for t eir intended purposes. This is particularly true-with respect to drawing temperatures, it having been found that unless such steels are drawn or quenched within a narrow range of temperature the desired physical properties are not attainedi It is also well known that the manufacture of sili-' co-manganese steels, particularly in the open hearth, requires careful attention because of the tendency to piping and segregation which results in the requirement that a large made in cropping the ingots.

The objectof the invention is to provide an alloy steel containing silicon and manganese in the proportions usually used in what .are commercially known as silico-manganese steel, and which has increased tensile strength and ductility, and is much less sen-, SltlVe to heating and heat treatment in its course of manufacture than are the usual silico-manganese steels.

"The steel alloy which we provide contains carbon from about 40% to .65%, manganese from about .50% to .80%, silicon from about 1.50% to 2. 10%,.and molybdenum from a Specification of Letters Patent. Patented Dec, 27, 1921, Application filed, June 14, 1920. Serial No. 888,787.

fraction of 1% The remainder of the alloy is iron with the exception of impurities, such as sulfur and phosphorus, which are usually found in steels. While the invention contemplates alloy steels of the range of analysis just stated, the preferred steel contains about .45% carbon, .6 5% manganese, 1.75% silicon and from about 30% to 1% of molybdenum.

Ve have found that the addition to silicomanganese steel of molybdenum in the proportions statednot only intensifies the physical properties of the steel, but also results in a steel having a wide range of hardening or quenching temperatures. WVith respect to the latter, the physical property curves of the present steel are of the same character as those shown in the Weitzenkorn Patent #1,287,153, in which the flattened curves clearly illustrate the uniform physical properties of the steelwhen drawn within a wide to not more than about 1.25%.

.40% to .65% carbon, .50% to .80% manganese, 1.50% to 2.10% silicon, a fraction of 1% to not more than about 1.25% molybdenum, and remainder ironexcept for impurities.

2. An alloy steel consisting of about .45

carbon, .65% manganese, 1.75% silicon, from about .30% to 1% molybdenum, and the remainder iron except for impurities.

In testimony set our hands.

GEORGE W. SARGENT.

JOSEPH W. VVEITZENKORN. Witnesses:

MARX Hanson,

WM. II.

whereof, we have hereunto- 

